Our understanding of the global epidemiology of periodontal disease has changed considerably over the past 50 years. This change has been influenced not only by our evolving knowledge of the natural history and distribution of the disease, but also by changing measurement methodologies. Although great strides have been made in describing the underlying contributions of microorganisms and plaque ecology, as well as the inflammatory and host responses, there is still much that is not known regarding risk susceptibility and prevention effectiveness. The focus of global periodontal epidemiology during the last half century has been on identifying populations who have periodontal disease and situations where disparities in disease prevalence exist between groups. Unlike dental public health activities directed toward dental caries, less effort has been made in periodontal epidemiology with regard to surveying or monitoring groups who may be at greater risk for moderate or severe disease and evaluating public health initiatives directed at mitigating risk or reducing such periodontal disease prevalence. Additionally, there is limited information regarding current national estimates of periodontal disease in most countries. Although numerous periodontal studies have been performed globally, very few are epidemiological studies using nationally representative samples. The aim of this critical review is to discuss the historical context of global periodontal disease epidemiology, highlight key activities and findings over the past decade in global periodontal epidemiology, and comment on how changes in the practice of epidemiology may affect global periodontology over the coming decade.